The present invention relates to a valve timing variation device which controls the timing of the opening and closing of a valve.
FIGS. 7 and 8 are cross sections showing a conventional valve timing variation device. FIGS. 9A and 9B are cross sections showing the structure of a chip seal of a valve timing variation device. In the figures, reference numeral 1 denotes an electronic control unit (hereafter ECU) which controls the oil control valve 2 and the like. 2 is an oil control valve (hereafter OCV) which supplies working oil to the actuator 3 under the control of the ECU 1. 3 is an actuator which controls the displacement angle of the camshaft 6 with respect to the timing pulley 8 when the working oil is supplied from the OCV 2 and which continuously regulates the timing of the opening and closing of the air intake valve. 4 and 5 are oil passages through which the working oil which is supplied from the OCV 2 flows. 6 is a camshaft which drives the opening and closing of the intake valve of the engine. 7 is a cam of the camshaft 6. 8 is a timing pulley arranged on one end of the camshaft 6. 9 is a bearing of the camshaft 6.
10 is a housing mounted so as to be freely rotatable with respect to the camshaft 6. 11 is a case fixed to the housing 10. 12 is a bolt which fixes the case 11 to the housing 10. 13 is a rotor which is fixed to the camshaft 6 and which rotates relative to the case 11. 14 and 16 are chip seals which prevent the movement of oil between the oil chambers 18 which are separated by the case 11 and the rotor 13. 15 is a metallic blade spring which is disposed between case 11 and the chip seal 14 and which pressures the chip seal 14 against the rotor 13. 17 is a metallic blade spring which is disposed between rotor 13 and the chip seal 14 and which pressures the chip seal 16 against the case 11. 18 are oil chambers which are separated by the case 11 and the rotor 13.
Next the operation of the invention will be explained.
Although the valve timing variation device controls the rotational direction of the housing 10 and the timing of the opening and closing of the air intake and exhaust valves of the engine by controlling of the amount of oil flowing into each oil chamber 18, in order to prevent the movement of oil between the oil chambers 18, a chip seal 14 is pushed against the rotor 13 and a chip seal 16 is pushed against the case 11.
In other words, as shown in FIG. 9A, the chip seal 14 is pushed against the rotor 13 by the blade spring 15 disposed between the case 11 and the chip seal 14. Furthermore the chip seal 16 as shown in FIG. 9B, is pushed against the case 11 by the blade spring 17 which is disposed between the rotor 13 and the chip seal 16.
The attachment of the chip seals 14 and 16 is performed by insertion between the case 11 and the rotor 13 in the direction from the left side of FIGS. 9A and 9B (the front of FIG. 8) to the right side (the back of FIG. 8) so that the chip seals 14, 16 and the metallic blade springs 15, 17 do not become disassembled.
Apart from the conventional example given above, a similar arrangement is disclosed in JP-A-9-324611.
Since conventional valve timing variation devices are constructed as above, chip seals 14, 16 are pushed onto the rotor 13 or the case 11 using blade springs 15, 17. However since the chip seals 14, 16 and the blade springs 15, 17 have different structures, the problem has arisen that assembly efficiency is extremely poor (for example when the chip seals 14, 16 are inserted the blade spring 15, 17 becomes detached and fall out) which reduces productivity.
The present invention is proposed to solve the above problems and has the objective of obtaining a valve timing variation device which can increase assemblying efficiency when the chip seals are assembled.
According to the first embodiment of the invention, the chip seal of the valve timing variation device has the shape of a letter xe2x80x9cLxe2x80x9d when taken in cross section.
According to the first embodiment of the invention, since the cross sectional shape of the chip seal has the shape of a letter xe2x80x9cLxe2x80x9d, the efficiency of assembling the chip seal can be increased.
According to the second embodiment of the present invention, the valve timing variation device is adapted to integrally form a chip seal and a flexible member.
According to the second embodiment, since the chip seal and the flexible member are formed integrally, assemblying efficiency of the chip seal is conspicuously increased.
According to the third embodiment of the present invention, the valve timing variation device is adapted to insert a blade spring into the chip seal.
According to the third embodiment, since the blade spring is formed to be inserted into the chip seal, it is possible to avoid the deficiency of the chip seal and the blade spring disassembling during assembly.
According to the fourth embodiment of the present invention, the valve timing variation device is adapted so that both legs of the chip seal are bent to form a flexible member.
According to the fourth embodiment, since both legs of the chip seal are bent to form a flexible member, it is possible to reduce manufacturing costs and at the same time conspicuously improve assembling efficiency of the chip seal.
According to the fifth embodiment of the present invention, the valve timing variation device is adapted to fix the flexible member which has lower hardness than the chip seal to the chip seal.
According to the fifth embodiment, by fixing the flexible member which has lower hardness than the chip seal to the chip seal, it is possible to lower manufacturing costs and to conspicuously increase assembling efficiency of the chip seal.
According to the sixth embodiment of the invention, the valve timing variation device adapted to construct the member on the rotor side of the chip seal using soft flexible resin.
According to the sixth embodiment, using soft flexible resin to construct the member on the rotor side of the chip seal enables the flexible member to be dispensed with.
According to the seventh embodiment of the present invention, the valve timing variation device is adapted so that the chip seal is pushed to the case side by the flexible member.
According to the seventh embodiment, since the chip seal is pushed to the case side by the flexible member, it is possible to prevent the movement of oil between the oil chambers which are separated by the case and the rotor.
According to the eighth embodiment, the valve timing variation device is adapted so that the chip seal is pushed to the rotor side by the flexible member.
According to the eighth embodiment, since the chip seal is pushed to the rotor side by the flexible member, it is possible to prevent the movement of oil between the oil chambers which are separated by the case and the rotor.